CiRt  unfl  N  i   104. 

United  States  Dcpan incut  of  Agriculture, 

BUREAU  OF  ENTOMOLOGY. 

L.  O.   HOWARD.  Entomologist  ami  Chief  of  Bui 


THE  COMMON  BED  SPIDER. 

(TrtrnniicliHM   bimariilatu*   ilnrvey.  1 


B     I'.  H.  Chittenden,  8c.  D., 
In  limn/I  nf  Truck  Crop  and  Special  Insect  (nrcxtinatioii*. 

I  \  l  HOD1  i  roHi . 

<  )nc  of  ilif  most  troublesome  of  greenhouse  pests  is  n  minute,  red- 
dish, spiderlike  creature,  known  popularly  as  "red  spider."  It  does 
very  considerable  damage  in  flower  and  vegetable  gardens,  and  in 
greenhouses  attains  it-  greatest  destructiveness.  It  is  particularly 
injurious  to  violets  and  roses,  and  attacks  n  great  variety  of  other 
plants,  including  shade  and  fruit  trees  and  some  field  crops.  Beans, 
cowpeas,  eggplant,  cucumber,  and  tomato,  especially  when  grown 
in  hothouses,  sustain  much  injury,  while  melon-,  squash,  and  berries 
are  subject  to  destructive  attack. 

Red  spiders  are  not  true  insects,  in  fact  not  even  spiders,  but  arc 
more  properly  speaking,  spinning  mites.  Since  however,  they  are 
almost  universally  known  as  "  red  spiders,"  this  term  is  retained. 

\  the  won!  "mite"  indicates,  these  insects  are  extremely  minute, 
and  when  they  occur  in  ordinary  numbers  are  not  apt  to  lie  noticed 
unless  the  leaves  are  carefully  scrutinized.  Attention,  however,  is 
certain  to  be  drawn  to  them  when  they  become  excessively  numerous, 
a-  frequently  happens  in  neglected  greenhouses  or  out  of  door-  during 
droughts  in  summer. 

Red  spiders  -pin  thread-,  hut  do  not.  like  true  spiders,  utilize  them 
For  climbing  or  for  descending  from  a  height.  The  threads  -pun  are 
'xtremely  line  and  scarcely  perceptible  to  the  unaided  eye.  hut  a  web 

■  Until  the  year  1000  tlie  common  red  spider,  most  often  occurring  in  _ 

rbnically  designated  a-  Tctranychu*  tiim-iu*  ]..,  n   uame  which 
!i  -  beeu  rather  Indiscriminately  applied  to  all  species  of  nil  spiders,  both  in 
America  ami  abroad. 
B4T51     dr.  i'*i 


of  threads  is  frequently  so  dense  as  to  form  a  tissue  plainly  visible  at 
a  little  distance.    Webs  arc  constructed  upon  the  lower  side  of  leave-. 

and  attached  here  and  there  to  projecting  hair-,  veins,  or  the  edge-  of 
the  leave-.  Within  the  webs  thus  formed  the  mites  feed  in  their 
different  stages,  and  the  eggs  are  laid  from  which  the  young  develop. 

DES<  i;iitj\  i.. 

The  general  appearance  of  this  red  spider  as  seen  under  a  micro- 
scope is  well  shown  in  figure  1.  u.  At  h  a  greatly  enlarged  palpus  of 
the  same  species  is  illustrated,  and  c  shows  the  claw-,  similarly 
enlarged. 

The  length  of  full-grown  individuals,  including  the  palpus,  i>  about 
T)'„  inch  (0.4  to  0.0  mmT.  and  the  width  about  1  fa  inch  (  0.25  to  0.30  mm), 
the  thickness  being  0.17  to  0.20  mm.     The  form   is  broadly  oval,  the 

width  greatest  in  the  anterior  third  of 
the  body,  back  of  the  eyes,  where  the 
side:-  are  somewhat  distended.  The 
general  color  of  the  adult  i>  reddish. 
usually  more  or  less  tinged  with  yel- 
lowish or  orange,  and  most  specimen- 
have  a  dark  spot  on  each  side,  due  to 
the  food  contents  of  the  body,  from 
which  the  scientific  name  himaculatus 
(two-spotted)    ha-  been  derived. 

Careful    study    of   different   individ- 
uals as  they  occur  on  garden  vegetables 
and  on  horticultural  and  other  plant  - 
growing  in  the  field  with  those  taken 
fig.    i.— The   common   rod   spider    m    ar-eenhouses   shows   no   appreciable 

(Tetraniicliu*      bimaculatUB)  :      ".       t  <*>  >  t  -» r       -v-      i 

\duit:  6,  palpus;  c,  claws,    a,    differences.     According  to  Mr.  Nathan 
Greatly  enlarged;  b,  c,  still  more    Banks,  specimens  taken  in  Florida  on 

enlarged.     (After  Banks.)  r  . 

Datura  and  at  Washington,  I).  C,  on 
violets  are  red.  while  those  from  Orono,  Maine,  and  those  from  the 
District  of  Columbia  on  squash  and  peach,  and  on  rose  from  Idaho, 
are  greenish  with  more  or  less  dark  markings. 

The  eggs  are  extremely  minute,  spherical,  of  variable  diameter. 
glassy,  and  are  scattered  and  loosely  attached  about  the  web-. 

The  young  are  somewhat  similar  in  appearance  to  the  adults,  but 
differ  in  having  only  three  pairs  of  legs,  while  the  adult  has  four 
pairs. 

DISTRIBUTION. 

This  red  spider  is  well  distributed  throughout  the  eastern  Ohited 
States,  and  was  identified  as  occurring  a>  far  west  a-  Idaho  in  1!>00. 
In  1002  it  was  recognized  from  Brighton.  Wash.;  in  1!>07  from  south- 

[Or.  104] 


era  California;  and  in  1908  at   Brownsville,  Tex.,  this  lasl  locality 
practically  assuring  its  occurrence  in  Mexico. 

\  \  I  I  l:i    01     i  Nil  B1  . 

The  red  spider  occurs  in  greenhouses  throughout  the  year,  and 
appears  to  be  nt  all  times  destructive  it'  permitted  i«>  propagate. 
I'tw  plants  are,  in  fact,  free  from  its  attack,  and  ii  is  found  in  mosl 
greenhouses.  When  only  a  few  mites  are  present  the  plants  seldom 
-how  :in\  external  evidences  of  injury,  but  as  thej  increase  in  number 
the  leaves  gradually  turn  paler  and  become  yellowish  and  stunted, 
Mini  soon  the  whole  plant  succumbs  unless  the  proper  remedies  are 
applied.  Cuttings  or  young  rooted  plum-  are  particularly  subject 
to  serious  injury,  and  this  is  especially  true  in  the  spring.  At  this 
time  the  mites  multiply  rapidly,  and  unless  plants  are  carefully 
watched  they  are  apt  to  become  so  badly  infested  that  it  is  only  with 
extreme  difficulty  that  they  can  be  restored  to  their  normal  growing 
condition. 

The  mites  injure  plants  by  suction,  and  when  they  occur  in  num- 
bers, which  they  almost  assuredly  do  when  plants  are  neglected,  the 
vitality  of  the  plants  is  slowly  1  n 1 1  surely  reduced  by  the  1"--  of 
the  juices,  and  in  time  ;ill  of  the  plants1  functions  arc  more  or  less 
deranged.  In  cases  of  severe  attack,  million-  of  red  spiders  can  l>e 
found  upon  the  foliage,  and  the  webs,  rarely  observable  at  ordinary 
times,  sometimes  stretch  from  plant  to  plant,  the  mites  passing  rap- 
idly over  them  and  congregating  in  -warm-. 

rooo  pi  w  i  s. 

The  red  spider  is  nearly  omnivorous,  attacking  a  wide  range  of 
both  glabrous  and  hirsute  plant-  belonging  to  many  families.  It  has 
been  observed  on  plant-  of  the  following  li-t :  Among  greenhouse  and 
other  ornamental  plant-,  roses,  violets,  carnation-  or  pink-,  mignon- 
ette, clematis,  pelargonium,  abutilon,  fuschia,  passiflora,  manettia, 
bonvardia,  feverfew,  verbena,  heliotrope,  salvia  or  sage,  morning- 
glory,  moonflower,  cypress-vine,  phlox,  chrysanthemum,  calla,  Easter 
lily,  Boston  smilax,  mimulus,  slipper  flower  (Calceolaria),  canary 
bird  {Tropaolium  peregrinum) ,  thunbergia,  wedding  bells  {Brug- 
mansia  arborea),  castor-oil  plant.  Asparagoides  plumo*a,  cuphea, 
godelia,  sunflower,  and  aster.  Of  the  plant-  listed,  violet-  and  roses 
are  very  susceptible  to  damage  by  the  red  spider,  more  especially 
when  the  plant-  are  growing  under  glass. 

if.  as  -.'.'m-i  probable,  Tt  tranychus  <  m  umeria  >>r  some  >ther  species  described 
by  Bolsduval  (Entom.  Horticole)  is  Identical  with  v.  bimoculatus,  ir  is  quite 
likely  that  this  red  spider  is  of  foreign  <>riirin  and  Introduced  int«>  the  United 
st;itrs.  which  is  true  of  a  very  large  proportion  <>f  greenhouse  and  other  Indoor 
Insects. 

|('ir.  104] 


Among  truck  and  vegetable  crops,  leguminous  giants  are  greatly 
injured,  more  especially  beans,  including  Lima  beans.  Cucumbers 
and  tomatoes  grown  in  hothouses,  cantaloupes  or  muskmelons,  water- 
melons, and  squash  are  also  badly  damaged.  Eggplant,  pepper, 
pepino  {Solanum  muricatum) ,  corn,  cowpeas,  raspberry,  strawberry, 
beets,  and  celery  are  also  subject  to  attack,  but  are  not  as  a  general 
ride  very  seriously  injured. 

Of  field  crops  infested  other  than  those  which  have  been  mentioned 
are  hops.  hemp,  peanut,  and  the  groundnut  or  wild  bean  (Apios 
i  pios ) . 

Trees  grown  for  shade  and  for  fruit  are  subject  to  attack  and  con- 
siderable injury  is  effected  at  times.  The  list  of  trees  that  have  come 
under  observation  as  subject  to  the  greatest  injury  includes  the  Ken- 
tucky coffee  tree  (Gymnocladus  canadensis),  the  hop  tree  (Ptelee 
trifoliata),  pecan,  ornamental  sassafras,  arborvitae,  maple,  horse- 
chestnut,  and  birch. 

INJURY  To  TRUCK  CRnl's. 

Every  year  this  species  i-  noted  in  considerable  numbers  on  the 
underside  of  leaves  of  bean  in  and.  about  the  District  of  Columbia. 
frequently  causing  great  blotches  and  the  withering  of  a  large  portion 
of  the  leaf.  When  the  mites  occur  in  such  abundance  it  necessarily 
causes  a  drain  on  the  vitality  of  the  plant  and  a  decrease  in  the  pro- 
ductiveness of  seed-pods  if  not  of  the  seeds  themselves.  Still,  as  a 
rule,  such  injury  is  rarely  noticed  until  comparatively  late  in  the  sea- 
son, in  September  and  October. 

Similar  injury  has  been  reported  in  Georgia  and  South  Carolina  to 
all  forms  of  beans — snap,  butter,  and  Lima— as  well  as  to  cowpeas. 
In  the  same  States  injury  has  been  reported  to  a  variety  of  other 
truck  crops.  Writing  in  June,  one  of  our  correspondents  stated  that 
his  cucumbers  looked  as  if  a  blight  were  on  them;  another  wrote: 
"  A  fine  garden  three  weeks  ago  now  looks  as  if  a  fire  had  struck  it." 

INJURY    TO    TREES. 

Injury  by  the  red  spider  to  shade  and  fruit  trees  is  insignificant, 
as  a  rule,  compared  with  that  which  is  accomplished  by  leaf-feeders 
such  as  caterpillars.  Sometimes,  however,  very  considerable  defolia- 
tion is  caused  by  the  attack  of  this  species.  This  was  very  noticeable 
during  the  summer  of  1906,  when  the  foliage  of  various  shade  trees 
in  the  city  of  Washington  was  injured.  Attack  was  first  observed 
during  the  third  week  in  July  and  was  manifested  by  the  leaves  hav- 
ing turned  yellow  on  the  upper  surface.  The  leaves  on  the  lower 
branches  showed  the  presence  of  numerous  feeding  colonies  The 
Kentucky  coffee  tree  suffered  most  of  all  of  our  city  trees.  On  one 
of  these  trees  the  leaves  continued  to  drop  throughout  the  remainder 
of  July  and  August,  but  by  September,  partly  owing  to  an  unpre- 
cedented rainfall  of  three  week-'  duration,  the  mites  were  less  in  evi- 
[Cir.  104  j 


,1,. ,,,,.  Bnd  many  branches  from  which  the  leave*  had  fallen  developed 
new  clusters  of  fresh  leave 

Two  vears  later  it  was  noticed  thai  manj  "I  the  lower  branches 
which  hail  suffered  most  from  defoliation  \>\  the  red  spider  were  dead, 


i'i,.    j      Kentucky    coffee   tree,   showing  !>:in  1:1 1   defoliation   bj  the   red   spider  on   lower 
branches;  upper  branches  bare  pnt  onl  oew  Original  I 

without  doubt  owing  t<>  the  attack  of  this  insect.     The  accompanying 
illustration  (tiir.  2)  was  taken  after  the  new  leave-  had  become  well 

[Or.  104] 


6 

developed.    Two  or  three  weeks  before  thai  time  the  lower  half  of 
the  tree  bore  only  ;i  few  leave-. 

This  same  form  of  injury  was  repeated  in  L908,  the  tree  looking 
considerably  worse  than  shown  in  figure  2. 

NATURAL    ENEMIES. 

The  predaceous  and  parasitic  inseci  enemies  of  the  red  spider,  men- 
tioned below,  were  observed  by  the  writer  on  the  Kentucky  coffee 
tree  at  Washington,  I).  C,  during  July  and  early  August,  VM'>. 

Scymnus  punctum  Lee,  a  very  small  black  ladybird,  was  observed 
July  21,  chiefly  as  a  nearly  full-grown  larva,  and  was  the  most  active 
natural  enemy.  At  that  time  it  was  for  the  most  part  attached  to  the 
leaves  for  pupation,  and  a  single  pupa  was  found  then  and  many  a 
few  days  later.  Nearly  all  the  larva'  had  transformed  and  the  beetles 
had  begun  to  issue  by  the  1st  of  September.  An  illustrated  account 
of  this  species  was  given  by  J.  C.  Duffey  in  1891." 

Cecidomyia  coccidarum  Ckll.  (  ?). — The  larva  of  this  small  cecido- 
myiid  fly  was  reared  at  Washington,  where  it  Avas  fairly  abundant. 
It  was  secondary  in  importance  only  to  the  ladybird  mentioned,  as  a 
destroyer  of  its  red-spider  host. 

With  the  hitter  was  reared  a  minute  chalcis  fly.  Aphanogmus  va- 
ripes  Ashm..  a  species  recorded  as  parasitic  on  ceeidomyiids. 

Chrysopa  ruflabris  Burm.,  a  lacewing  fly.  was  also  reared  and  the 
larva  was  observed  in  numbers  attacking  the  red  spider. 

Thrips  sexmaculata  Perg.  has  been  recorded  as  an  enemy  of  the 
red  spider  by  Pergande  B  and  by  Duffey. 

METHODS    oi'    CONTROL. 
DIBECT    REMEDIES. 

Eed  spiders  are  more  resistant  to  fumigation,  either  with  tobacco 
or  hydrocyanic-acid  gas.  than  are  aphides,  thrips.  and  small  forms 
of  insects  generally.  Only  a  portion  of  these  creatures  are  usually 
killed  by  the  ordinary  use  of  the  gas  in  greenhouses — never  more  than 
80  per  cent,  so  far  as  our  records  go.  The  remainder  may  be  stupefied 
for  a  time,  but  eventually  recover.  They  are.  however,  extremely 
sensitive  to  sulphur,  applied  either  dry  or  as  a  wash,  or  in  connection 
with  other  poisons.     Soap  is  also  a  good  remedy. 

Sulphur. — Flowers  of  sulphur,  mixed  with  water  at  the  rate  of  an 
ounce  to  a  gallon,  and  sprayed  over  infested  plants,  is  of  great  value 
in  the  eradication  of  this  pest;  or  the  sulphur  may  be  combined  with 
strong  soapsuds.  For  the  application  of  this  spray  a  force  pump 
with  spraying  nozzle  is  a  necessity  and  the  current  should  always  be 
directed  to  flic  lower  surface  of  the  leaves. 

Son/)  solutions. — Potash,  fish-oil,  whale-oil.  and  other  soap  dilutions 
are  valuable  against  the  red  spider,  and  the  addition  of  sulphur  in- 

"  Trans.  St.  Louis  Acad.  s.i..  Vol.  V.  pp.  540-542.        6  Psyche,  Vol.  III.  i>.  .".si.  L882. 
[Cir.  KM] 


creases  their  effectiveness;  bul  these  washes  will  injure  -nine  delicate 
plants.  Moreover,  they  have  no  more  value  as  insecticides  than 
neutral  soaps  of  the  castile  and  Ivorj  type,  or  such  as  are  used  bj 
physicians  and  surgeons. 

For  i  lif  red  spider,  as  n  occurs  in  greenhouses,  particular!}  <  m  pi  nut-. 
such  as  violets,  thai  are  liable  to  injury  from  sulphur,  no  other  rem- 
edy is  employed  bj  florists  generally  than  frequent  syringing  or  spraj 
ing  with  water  or  with  ;i  soap  solution.  Neutral  — < »i* j »—  are  valuable, 
particularly  upon  cuttings  affected  with  the  red  spider,  and  the  bes< 
results  have  been  obtained  in  the  proportion  of  a  5  cenl  cake  to  6  <>r  7 
gallons  of  water.  The  soap  i-  shaved  with  ;i  small  plane,  dissolved 
in  about  m  gallon  of  lift  water,  and  then  sufficient  cold  water  is  added 
to  make  the  quantity  desired.  Five  gallons  arc  sufficient  for  the  treat 
iiu'iit  of  three  or  four  thousand  cuttings  of  violets.  It  is  customary 
to  allow  the  soap  to  remain  on  the  plant-  two  or  three  hours  and  then 
to  syringe  thoroughly   with  clear  water,  repeating  this  treatment 

two  or  three  times,  until  the  "spiders"  and  their  eggs  have  I n 

destroyed.  Used  thus,  the  soap  has  little  if  any  deleterious  effect 
upon  most  plant-. 

Kerosene-soap  emulsion. — An  emulsion  may  l>e  prepared  by  com- 
bining 2  gallons  of  kerosene  and  one-half  pound 
<it'  whale-oil  soap  (or  1  quart  of  soft  soap)  with  l 
gallon  of  water.  The  soap  i-  dissolved  in  boiling 
water  and  then  poured  while  -till  boiling  hot 
(away  from  the  lire)  into  the  kerosene.  The  mix- 
ture is  churned  rapidly  for  five  or  ten  minute-. 
pumping  the  liquid  back  upon  itself  by  mean-  of 
a  force  pump  and  direct-discharge  nozzle  throw- 
ing a  strong  stream.  At  the  end  of  this  time  the 
mixture  will  have  the  consistency  of  thick  cream. 
Properly  prepared,  an  emulsion  will  keep  almost  indefinitely,  and 
should  be  diluted  as  needed  for  use.  For  the  red  spider  the  staple 
emulsion  should  be  diluted  with  about  10  part-  of  water.  In  the 
preparation  of  kerosene  emulsion  a  force  pump  is  required,  since  if 
not  made  according  to  directions  a  perfect  emulsion  is  not  formed  and 
there  is  then  danger  of  injury  to  the  plants  or  useless  wa-te.  There  i- 
danger  and  wa-te.  too.  if  the  insecticide  is  not  applied  by  mean-  of  a 
tine  nozzle  in  the  form  of  a  Spray,  which  should  he  line  and  mi-tdike. 
It  should  l»e  -prayed  only  for  a  sufficient  time  to  cover  the  plants; 
otherwise  the  liquid  form-  into  globules  and  run-  off.  An  eltxro 
attachment  for  underspraying  i-  shown  in  figure  :'>. 

Lye-sxilphur.—The  lye-sulphur  remedy  was  given  a  thorough  "test 
against  the  red  spider  in  it-  occurrence  on  beans  in  Florida,  having 
been  applied  May  28,  1908,  with  the  result  that  98  per  cent  of  the  red 
spiders  were  killed  without  in  the  least  affecting  the  plant-  treated. 

[Or.  KM] 


Pig  "•.  Elbow  attach 
ment  f<>r  undi  r 
Bpraj  in-      Reduced 


8 

This  shows  better  results  than  with  any  of  the  four  insecticides 
which  were  tested  in  that  locality  by  Mr.  II.  M.  Russell,"  :*>  per  cent 
more  of  the  mites  being  destroyed  than  by  the  use  of  kerosene  emul- 
sion, which  slightly  injured  the  plants;  7  per  cent  more  than  with  the 
use  of  sulphur  water,  and  it  proved  to  be  much  better  than  lime- 
sulphur,  which  was  hardly  a  success  as  compared  with  the  other-. 
Lye-sulphur  is  prepared  as  follows: 

.Mix  L'o  pounds  of  flowers  of  sulphur  into  a  paste  with  cold  water;  then  add 
10  pounds  of  pulverized  caustic  soda  (98  per  cent).  The  dissolving  lye  will 
boil  and  liquefy  the  sulphur.  Water  must  he  added  from  time  to  time  to  pre- 
vent burning,  until  n  concentrated  solution  of  20  gallons  is  obtained.  Two  gal- 
lons of  this  is  sufficient  for  50  gallons  of  spray,  giving  a  strength  of  2  pounds  of 
sulphur  and  1  of  lye  to  50  gallons  of  water.  An  even  stronger  application  can 
be  made  without  danger  to  the  foliage.  This  mixture  can  also  bo  used  in  com- 
bination with  other  insecticides  (Marlatt,  Farmers1  Bulletin  172). 

Tobacco  voter. — Tobacco  water  is  of  some  use  for  destroying  the 
red  spider,  but  can  not  be  recommended  for  violets,  owTing  to  it- 
tendency  to  weaken  the  foliage  and  induce  "  -pot." 

Water. — Spraying  with  water  is  usually  practiced  two  or  three 
times  a  week  during  the  growing  season,  and  by  a  little  practice  and 
experiment  with  a  fine-spray  nozzle  or  tip  the  operator  is  soon  able 
to  ascertain  the  proper  degree  of  force  to  use.  A  pressure  of  about  •_'•"> 
pounds  has  proved  most  effective  against  this  red  spider.  Care 
should  be  exercised  to  wash  off  the  "  spiders  "  and  at  the  same  time 
to  avoid  drenching  the  beds.  When  it  is  necessary  to  spray  during 
winter,  work  should  be  done  on  a  bright  day,  in  order  that  the  plant - 
may  dry  off  in  a  few  hours.  Water  is  also  of  use  on  shade  trees  and 
shrubs  in  parks. 

NOZZLE    AND    TIP    FOB    GREENHOUSE    USE. 

Since  the  general  adoption  of  spraying  as  a  remedy  for  the  red 
spider,  the  problem  of  how  to  apply  a  water  or  other  spray  so  as  not 
to  drench  the  beds  has  been  an  important  one.  To  accomplish  this 
object,  Dr.  B.  T.  Galloway.  Chief  of  the  Bureau  of  Plant  Industry, 
has  devised  a  small  -praying  tip  which  answers  the  purpose  ad- 
mirably, being  particularly  serviceable  where  plant-  are  syringed  or 
sprayed  on  a  large  scale.  The  following  description  of  the  nozzle  is 
taken  from  Circular  17  of  the  Division  of  Vegetable  Physiology  and 
Pathology  : 

The  spray  tip  proper  is  attached  to  a  brass  fitting,  which  in  turn  screws  onto 
the  end  of  a  three-quarter-inch  hose.  The  apparatus  is  very  effective  for  spray- 
ing.roses,  as  it  readily  serves  to  keep  the  leaves  in  a  thoroughly  healthy  condi- 

"  For  particulars  see  article  by   II.   M.  Itussell   in  Journal  of  Economic   En- 
tomology, Vol.  I,  pp.  377-380,  1908. 
[Ctr.  104] 


Hon,  a  ml  at  tin-  aanie  time-  wets  the  1  •  •  -« i  —  bill  little,  li  Is  also  rerj  nseful  for 
violets,  as  with  a   pressure  of  38  i"   K)  pounds  the  the  plan!  can  be 

readily  turned  over  and  thoroughly  washed  without  Booking  the  crowns  nnd  the 

bed.     in  spraying  a e  plants,  particularly  violets,  it   bas  been  found  ad  van 

tageoua  to  use  a  lance  Is  Inches  long,  made  •  •(  a  p  le  half  Incb  bi 

pipe.    This  Increases  the  reach,  nnd  enables  the  operator  m  place  the  wain  to 

better  ad  van  tag plants  which  under  ordinary   conditions  would  !»■  beyi 

arm's  length.  The  apparatus  can  be  made  for  60  cents,  and  will  be  found  a 
useful  Instrument  wherever  there  Is  sufficient  water  pressure  to  Insure  a  proper 
amount  of  force. 

The  illustration  here  presented  (fig.  li  shows  the  general  appear- 
ance of  this  i  i|>  and  nozzle.  The  nozzle  consists  of  a  casting  turned  i<> 
the  desired  length  and  Battened  at  the  end  as  figured.  Through  this 
flattened  end  ;i  narrow  -lit  is  made,  which  should  be  absolutely  true 
throughout,  so  thai  the  water  as  it  issues  will  be  broken  up  into 
streams.  It  is  even  sometimes  necessary  to  file  t Ik-  tips  as  they  come 
From  ili»'  Factory,  to  secure  the  desired  result. 

iki  \i  mi  \  i    ui     rancs    ikd   bbbubs. 

The  methods  of  control  which  have  been 
advised  above  are  especially  adapted  to  the 
treatment  of  greenhouses  infested  l>\  the 
spider.  All  of  the  insecticides  which  have 
been  recommended  for  indoor  use  are  also 
applicable  to  trees  and  shrubs,  the  list  in- 
cluding sulphur,  which  m;i\  be  applied  in 
the  form  of  a  powder  by  means  of  a  pow 
dcr  bellows,  or  mixed  with  water  as 
previously  prescribed,  or  combined  with 
lye  or  lime.  Soap  solutions,  kerosene 
emulsion,  and  cold  water  maj  be  used  with 
profit.  Resin  wash  and  lime-sulphur  are 
also  used  as  for  the  orange  mites  or  red  spiders.  Of  these  the  lye- 
sulphur  mixture  is  probably  the  best,  as  it  is  successfully  used  against 
these  pests  in  California. 

The  sulphur  treatment  has  an  advantage,  in  that  it  adheres  mure 
closely  to  the  leave-  than  other  preparation-  which  have  been  men- 
tioned and  kills  young  mites  coming  in  contact  with  it  as  -non  as 
they  are  hatched.  Sulphur  preparation-  are  also  of  value  in  eradi- 
cating scale  insects  which  mighl  be  present  at  the  same  time;  in  fact, 
when  the  sulphur  i-  being  applied  for  scale-insects,  red  spiders  or 
mites  are  likewise  killed. 

na  \  l  mini    ni     ii;iik     \M>   GARDEN    PI  \\ 

In  the  treatment  of  truck  crop-  infested  by  the  nM  spider,  little 
variation  from  the  method-  already  advised  for  greenhouse  work 
need  be  practiced.     The  same  applies  to  ornamental  flowering  plants 

[Cir.    104] 


li..      4       Nozxle     ;in<I     tip     for 
greenhous     is       Red  need 


Ill 

iii  gardens.  Considering  the  great  susceptibility  to  damage  from  red 
spider  of  beans,  cowpeas,  and  other  leguminous  crops,  and  orna- 
mental plants,  it  is  advisable,  where  this  mite  is  very  destructive,  as 

in  the  District  of  Columbia  and  southward,  to  practice  rotation  with 
plants  not  so  subject  to  injury.  The  lye-sulphur  lcunedy  has  pro- 
duced the  best  results,  as  ju>t  described.  Some  of  the  remedial  meas- 
ures advised  for  the  cotton  red  spider  (Tetranyckus  gloveri  Bks.), 
a  related  species  occurring  in  the  (iulf  region,  may  lie  followed;  in- 
deed, the  same  measures  are  applicable  to  aphides  and  other  pests 
which  may  be  present  on  the  plants  at  the  same  time. 

Among  cultural  methods  of  control  may  be  mentioned  clean  garden 
ing  or  farming  with  early  fall  plowing,  keeping  down  the  weeds  of  the 
vicinity  throughout  the  year,  and  destroying  crop  remnants  as  early 
as  possible  by  burning  or  otherwise.  Weeds  growing  on  the  edges  of 
fields,  in  fence  corners,  and  like  locations  should  lie  destroyed  early  in 
the  fall  in  order  that  no  winter  shelter  may  be  left  for  the  pests. 
Early  fall  plowing  destroys  the  insects  before  they  have  an  opportu- 
nity to  leave  the  old  crop  plants  for  weeds  and  others. 

During  May,  1908,  Mr.  H.  M.  Russell,  working  under  the  writer's 
direction  at  Orlando.  Fla.,  conducted  some  experiments  with  reme- 
dies against   the  red   spider   in   its  occurrence  on    wax   beans.     The 
results  obtained,  in  brief,  are  as  follows: 
Kerosene-soap   emulsion,    1    part    stock    solution    to   10    parts 

water,  killed 95  per  cent. 

Lye-sulphur,  1  pound  sulphur,  i  pound  lye,  to  4<>  gallons  water. 

killed _ 98  per  cent. 

Sulphur  water,  1  ounce  to  1  gallon  water,  killed '-'1  percent. 

Lime-sulphur,  1  pound  lime,  1   pound  sulphur,  to  -'>  gallons 
water,  killed (is  to  85  per  cent. 

The  results  show  that  the  red  spider  succumbs  to  any  one  of  these 
four  insecticides,  the  probabilities  being  that  kerosene-soap  emul- 
sion, properly  prepared  and  applied,  is  as  satisfactory  a  remedy  as 
any  other  applications  that  could  be  employed. 

St   MM  AH  V. 

The  remedies  advised  may  be  summarized  as  follows: 

For  the  greenhouse  and  for  general  use.  sulphur  and  neutral,  whale- 
oil,  and  other  soap  solutions,  kerosene-soap  emulsion,  and  spraying 
with  water. 

For  the  treatment  of  trees  and  shrubs,  the  same  as  the  above,  with 
the  addition  of  resin  wash  and  the  lime-sulphur  and  lye-sulphur 
mixtures. 

For  truck  a"nd  garden  plants,  lye-sulphur  wash  and  the  same 
remedies  as  for  the  greenhouse,  with  the  addition  of  clean  gardening 
[Cir.  104] 


MARSTON  SCIENCE  LIBRARY 


Date 

Due 

i 

Due 

Returned 

Due 

Returned 

;.. 

m  ?i  m 

MAR  0  2  1995 

n 

t  •  •**» 

■,l 

MOMENT 


umvERsmr  of  florid* 


3    1262    05252    3411 


